* "I am both a quick worker and a careful one." This uses the pair "both...and" and makes the sentence parallel by using the adjective "quick" to describe the noun "worker" and "careful" to describe the noun "one" (which stands in for "worker").
* "I am not only a quick worker but also a careful one." This uses the pair "not only...but also" and follows the same parallel structure as the previous example.
* "I am as quick as I am careful." This uses the pair "as...as" and emphasizes the equal balance of quickness and carefulness.
The best option depends on the specific nuance you want to convey. Let me know if you have any other sentences you'd like help with!